The present disclosure relates to a display device which can be applied to a liquid crystal display device that performs intermittent driving.
It is imperative that liquid display devices for mobile terminals such as smartphones and tablet terminals reduce power consumption by circuits. As methods for reducing power consumption, low-frequency driving and intermittent driving have been proposed. The low-frequency driving is a scheme for reducing a driving frequency of a liquid crystal display device to ½, ¼, or the like of a standard condition and thereby reducing circuit power. The intermittent driving is a scheme for reducing circuit power by setting several display time periods in which circuits are stopped after a liquid crystal display device performs writing for one display time period. Both schemes may elongate time intervals at which an image signal is rewritten in a liquid crystal display unit, thereby causing an adverse effect such as blurring of a video image. However, the schemes are effective to reduce circuit power for displaying still images in which video image visibility is not important.
A liquid crystal display device disclosed in International Publication No. WO2013/021576 switches a refresh (frame) frequency according to an image to be displayed. A frame frequency of 60 Hz (normal driving) is used for displaying video images, while a frame frequency of 1 Hz (intermittent driving) is used for displaying still images.
Hereinafter, regarding the low-frequency driving and the intermittent driving, a time interval at which an image signal of a pixel is rewritten is referred to as a “frame cycle” or “one frame”, and the inverse of the time interval is referred to as a “frame frequency”.